merge: testing → main (reconcile 2-week divergence)

decnet/web/router/topology/api_create_topology.py

@@ -0,0 +1,77 @@
+"""POST /topologies — generate and persist a new MazeNET topology."""
+from __future__ import annotations
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.exc import IntegrityError
+
+from decnet.telemetry import traced as _traced
+from decnet.topology.allocator import reserved_subnets
+from decnet.topology.config import TopologyConfig
+from decnet.topology.generator import generate
+from decnet.topology.persistence import persist
+from decnet.web.db.models import TopologyGenerateRequest, TopologySummary
+from decnet.web.dependencies import repo, require_admin
+from decnet.web.router.topology._target_host import validate_target_host
+
+router = APIRouter()
+
+
+@router.post(
+    "/",
+    tags=["MazeNET Topologies"],
+    response_model=TopologySummary,
+    status_code=status.HTTP_201_CREATED,
+    responses={
+        400: {"description": "Malformed or invalid generation parameters"},
+        401: {"description": "Missing or invalid credentials"},
+        403: {"description": "Insufficient permissions"},
+        409: {"description": "Duplicate topology name, or generator could not allocate subnets (exhausted pool)"},
+    },
+)
+@_traced("api.topology.create")
+async def api_create_topology(
+    body: TopologyGenerateRequest,
+    _admin: dict = Depends(require_admin),
+) -> TopologySummary:
+    await validate_target_host(repo, body.mode, body.target_host_uuid)
+    try:
+        config = TopologyConfig(
+            name=body.name,
+            mode=body.mode,
+            depth=body.depth,
+            branching_factor=body.branching_factor,
+            deckies_per_lan_min=body.deckies_per_lan_min,
+            deckies_per_lan_max=body.deckies_per_lan_max,
+            bridge_forward_probability=body.bridge_forward_probability,
+            cross_edge_probability=body.cross_edge_probability,
+            services_explicit=body.services_explicit,
+            randomize_services=body.randomize_services,
+            seed=body.seed,
+        )
+    except (ValueError, TypeError) as exc:
+        raise HTTPException(status_code=400, detail=str(exc)) from exc
+
+    try:
+        plan = generate(config, reserved_subnets=await reserved_subnets(repo))
+    except RuntimeError as exc:
+        # Subnet allocator exhaustion or similar planner-level failure.
+        raise HTTPException(status_code=409, detail=str(exc)) from exc
+    except (ValueError, TypeError) as exc:
+        raise HTTPException(status_code=400, detail=str(exc)) from exc
+
+    try:
+        topology_id = await persist(repo, plan, target_host_uuid=body.target_host_uuid)
+    except IntegrityError as exc:
+        # Unique constraint on topologies.name is the only integrity
+        # error the create path can realistically hit — inspecting the
+        # constraint name keeps us from silently mapping unrelated
+        # integrity failures to 409.
+        msg = str(exc.orig) if exc.orig is not None else str(exc)
+        if "ix_topologies_name" in msg or "topologies.name" in msg:
+            raise HTTPException(
+                status_code=409,
+                detail=f"A topology named {body.name!r} already exists.",
+            ) from exc
+        raise
+    row = await repo.get_topology(topology_id)
+    return TopologySummary(**row)